Method for performing preview control in an electronic device, and associated apparatus

ABSTRACT

A method for performing preview control in an electronic device and an associated apparatus are provided, where the method may include the steps of: obtaining a specific preview image from a camera module of the electronic device, and obtaining a specific focus-related parameter corresponding to the specific preview image, wherein the specific focus-related parameter is related to focus control of the camera module; determining a specific resize parameter corresponding to the specific preview image according to a predetermined relationship between the specific resize parameter and the specific focus-related parameter; and performing a resize operation on the specific preview image according to the specific resize parameter, to control the specific preview image to be displayed in a quasi-scale-invariant manner with respect to a plurality of preview images.

BACKGROUND

The present invention relates to camera control in a portable electronicdevice such as a multifunctional mobile phone, and more particularly, toa method for performing preview control in an electronic device, and anassociated apparatus.

Autofocus procedure of a camera device changes the scale of capturedcontent with respect to focus settings. In a situation where the previewimages are displayed during a convention autofocus procedure of theconventional portable electronic device, the scale of captured contentvaries with respect to focus settings, since the focus distance, i.e.between the camera lens and the image sensor, varies with focus settingsin response to the autofocus procedure. As a result, staring at thepreview frames that are scale-variant in the related mechanism, a usermay feel visually annoyed that leads to dissatisfied user experience. Tothis end, we propose a novel architecture to enhance the overallperformance of an electronic device without introducing other sideeffects.

SUMMARY

It is therefore an objective of the claimed invention to provide amethod for performing preview control in an electronic device, and anassociated apparatus, in order to solve the above-mentioned problems.

It is another objective of the claimed invention to provide a method forperforming preview control in an electronic device, and an associatedapparatus, in order to enhance the overall performance of the electronicdevice without introducing any side effect.

According to at least one preferred embodiment, a method for performingpreview control in an electronic device is provided, where the methodcomprises the steps of: obtaining a specific preview image from a cameramodule of the electronic device, and obtaining a specific focus-relatedparameter corresponding to the specific preview image, wherein thespecific focus-related parameter is related to focus control of thecamera module; determining a specific resize parameter corresponding tothe specific preview image according to a predetermined relationshipbetween the specific resize parameter and the specific focus-relatedparameter (e.g. the mapping of the specific resize parameter and thespecific focus-related parameter associated with the specific resizeparameter); and performing a resize operation (e.g. an image resizeoperation) on the specific preview image according to the specificresize parameter, to control the specific preview image to be displayedin a scale-invariant manner with respect to a plurality of previewimages. In some embodiments, the scale-invariant manner may be replacedby a quasi-scale-invariant manner, and this quasi-scale-invariant mannermay represent that a difference between a scale of the specific previewimage and a scale of any preview image (e.g. any of the plurality ofpreview images) falls within a range of a predetermined interval.

According to at least one preferred embodiment, an apparatus forperforming preview control in an electronic device is also provided,where the apparatus comprises at least one portion of the electronicdevice. The apparatus comprises a focus control module and a resizecontrol module that is coupled to the focus control module, and furthercomprises an image resize module that is coupled to the resize controlmodule. More particularly, the focus control module is arranged forcontrolling the apparatus to obtain a specific preview image from acamera module of the electronic device, and is further arranged forobtaining a specific focus-related parameter corresponding to thespecific preview image, wherein the specific focus-related parameter isrelated to focus control of the camera module. In addition, the resizecontrol module is arranged for determining a specific resize parametercorresponding to the specific preview image according to a predeterminedrelationship between the specific resize parameter and the specificfocus-related parameter (e.g. the mapping of the specific resizeparameter and the specific focus-related parameter). Additionally, theimage resize module is arranged for performing a resize operation (e.g.an image resize operation) on the specific preview image according tothe specific resize parameter, to control the specific preview image tobe displayed in a scale-invariant manner with respect to a plurality ofpreview images. In some embodiments, the scale-invariant manner may bereplaced by a quasi-scale-invariant manner, and thisquasi-scale-invariant manner may represent that a difference between ascale of the specific preview image and a scale of any preview image(e.g. any of the plurality of preview images) falls within a range of apredetermined interval.

According to at least one preferred embodiment, a method for performingpreview control in an electronic device is provided, where the methodcomprises the steps of: obtaining a specific preview image from a cameramodule of the electronic device, and obtaining a specific focus-relatedparameter corresponding to the specific preview image, wherein thespecific focus-related parameter is related to focus control of thecamera module; determining a specific resize parameter corresponding tothe specific preview image according to a predetermined relationshipbetween the specific resize parameter and the specific focus-relatedparameter (e.g. the mapping of the specific resize parameter and thespecific focus-related parameter associated with the specific resizeparameter); and performing a resize operation (e.g. an image resizeoperation) on the specific preview image according to the specificresize parameter, to control the specific preview image to be displayedin a quasi-scale-invariant manner with respect to a plurality of previewimages. For example, this quasi-scale-invariant manner may representthat an image scale difference between the specific preview image andany preview image (e.g. any of the plurality of preview images) fallswithin a predetermined range.

It is an advantage of the present invention that the present inventionmethod and the associated apparatus can enhance the overall performanceof the electronic device without introducing any side effect. Inaddition, in comparison with the related art, the present inventionmethod and the associated apparatus can bring better user experience,where the potential problems of related art can be prevented.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an apparatus for performing preview control in anelectronic device according to an embodiment of the present invention.

FIG. 2 illustrates a flowchart of a method for performing previewcontrol in an electronic device according to an embodiment of thepresent invention.

FIG. 3 illustrates the visual effect of a scale-invariant control schemeaccording to an embodiment of the present invention.

FIG. 4 illustrates an image signal processor (ISP) involved with themethod shown in FIG. 2 according to an embodiment of the presentinvention.

FIG. 5 illustrates a set of predetermined relationships involved withthe method shown in FIG. 2 according to an embodiment of the presentinvention.

FIG. 6 illustrates an ISP involved with the method shown in FIG. 2according to another embodiment of the present invention.

FIG. 7 illustrates a sensor system on chip (SOC) architecture involvedwith the method shown in FIG. 2 according to another embodiment of thepresent invention.

FIG. 8 illustrates a working flow involved with the method shown in FIG.2 according to an embodiment of the present invention.

FIG. 9 illustrates a working flow involved with the method shown in FIG.2 according to another embodiment of the present invention.

DETAILED DESCRIPTION

Certain terms are used throughout the following description and claims,which refer to particular components. As one skilled in the art willappreciate, electronic equipment manufacturers may refer to a componentby different names. This document does not intend to distinguish betweencomponents that differ in name but not in function. In the followingdescription and in the claims, the terms “include” and “comprise” areused in an open-ended fashion, and thus should be interpreted to mean“include, but not limited to . . . ”. Also, the term “couple” isintended to mean either an indirect or direct electrical connection.Accordingly, if one device is coupled to another device, that connectionmay be through a direct electrical connection, or through an indirectelectrical connection via other devices and connections.

FIG. 1 is a diagram of an apparatus 100 for performing preview controlin an electronic device according to an embodiment of the presentinvention, where the apparatus 100 may comprise at least one portion(e.g. a portion or all) of the electronic device. For example, theapparatus 100 may comprise a portion of the electronic device mentionedabove, and more particularly, can be at least one hardware circuit suchas at least one integrated circuit (IC) within the electronic device. Inanother example, the apparatus 100 can be the whole of the electronicdevice mentioned above. In another example, the apparatus 100 maycomprise a system comprising the electronic device mentioned above (e.g.an audio/video system comprising the electronic device). Examples of theelectronic device may include, but not limited to, a digital camera, amobile phone (e.g. a multifunctional mobile phone), a personal digitalassistant (PDA), and a personal computer such as a laptop computer.

As shown in FIG. 1, the apparatus 100 may comprise a focus controlmodule 110, a resize control module 120, and an image resize module 130,where the focus control module 110 and the resize control module 120 arecoupled to a scale-invariant control circuit 140, and the image resizemodule 130 is coupled to the resize control module 120. Moreparticularly, the focus control module 110 is arranged for enabling theapparatus 100 to obtain a specific preview image from a camera module 50of the electronic device, and the focus control module 110 is furtherarranged for setting a specific focus-related parameter corresponding tothe specific preview image. The specific focus-related parameter fromthe scale-invariant control circuit 140 is related to focus control ofthe camera module 50. The focus control module 110 may apply at leastone focus setting (e.g. one or more focus settings) to the camera module50, and the camera module 50 gets the specific preview image based onthe focus setting, wherein the specific preview image can be derivedfrom a user using the apparatus 100 (such as a digital camera) to take aphoto.

In addition, the scale-invariant control circuit 140 is arranged fordetermining a specific resize parameter corresponding to the specificpreview image according to a predetermined relationship between thespecific resize parameter and the specific focus-related parameter,Thus, the resize control module 120 may apply at least one resizesetting to the image resize module 130 according to the specific resizeparameter.

The image resize module 130 is arranged for performing a resizeoperation on the specific preview image according to the resize setting,to control the specific preview image to be displayed in ascale-invariant manner with respect to a plurality of preview images,where the preview images are obtained from the camera module 50, and thepreview images comprise the specific preview image. As a result, theresized images are generated and output by the image resize module 130.

In practice, the signal S shown in FIG. 1 may carry at least one focuscontrol result, which may come from either automatic or manual focusprocess of the camera module 50, which is the input to thescale-invariant control circuit 140 for the aforementionedscale-invariant manner. Autofocus process sets the signal to obtain aseries of preview images of different focus settings and performautofocus statistics analysis to get the best focused image.Manual-focus control signal corresponding to at least one user input canbe obtained from a user interface (UI) of the electronic device (e.g. aset of physical buttons of the electronic device, or a set of virtualbuttons displayed on a touch display module of the electronic device).This is for illustrative purposes only, and is not meant to be alimitation of the present invention.

Please note that the apparatus 100 may comprise the camera module 50mentioned above, for example. In some examples, the camera module 50 canbe positioned outside the apparatus 100, where the camera module 50 canbe coupled to the apparatus 100 in these examples.

According to some embodiments, the resize control module 120 can beintegrated into the focus control module 110. According to otherembodiments, it is unnecessary that the resize control module 120 isintegrated into the focus control module 110.

The focus control module 110, the resize control module 120, and theimage resize module 130 can be positioned within an image signalprocessor (ISP) (not shown), where the ISP can be coupled to the cameramodule 50. According to some embodiments, it is unnecessary that all ofthe focus control module 110, the resize control module 120, and theimage resize module 130 are positioned within an ISP.

The camera module 50 may comprise a lens unit, an image sensor, and anautofocus actuator that are arranged for obtaining the specific previewimage, where the focus control module 110, the resize control module120, and the image resize module 130 can be integrated into the imagesensor. For example, the lens unit may comprise a single lens. In someexamples, the lens unit may comprise a set of lenses. An autofocusactuator is used to adjust the image distance, i.e. the distance betweenthe lens and the sensor to converge light to the sensor plane so as toobtain a sharp image. Current producible actuators may include voicecoil motor, piezoelectric actuator autofocus, stepper motor, and MEMS(microelectromechanical systems)-based autofocus actuators.

There is an autofocus control circuit (not shown in FIG. 1) arranged forperforming the aforementioned autofocus control of the camera module 50,and there is an autofocus statistics module (not shown in FIG. 1), wherethe autofocus control circuit can be coupled between the camera module50 and the scale-invariant control circuit 140. More particularly, theautofocus statistics module is arranged for performing a plurality ofautofocus statistics operations on the plurality of preview images togenerate a plurality of autofocus statistics results, respectively, foruse of the aforementioned autofocus control. This is for illustrativepurposes only, and is not meant to be a limitation of the presentinvention.

FIG. 2 illustrates a flowchart of a method 200 for performing previewcontrol in an electronic device according to an embodiment of thepresent invention. The method 200 can be applied to the apparatus 100shown in FIG. 1, and can be applied to the focus control module 110, theresize control module 120, and the image resize module 130 thereof. Themethod can be described as follows.

In Step 210, the focus control module 110 controls the apparatus 100 toobtain a specific preview image from the camera module 50 of theelectronic device, and obtains the specific focus-related parametercorresponding to the specific preview image, where the specificfocus-related parameter is related to the focus control of the cameramodule 50.

In Step 220, the resize control module 120 determines the specificresize parameter corresponding to the specific preview image accordingto the predetermined relationship between the specific resize parameterand the specific focus-related parameter.

In Step 230, the image resize module 130 performs the resize operationon the specific preview image according to the specific resizeparameter, to control the specific preview image to be displayed in thescale-invariant manner with respect to a plurality of preview images(i.e. other preview images).

In other embodiments, the manner to eliminate user's visually annoyedfeeling could also be implemented by that a difference between the scaleof the specific preview image and the scale of any preview image (e.g.any of the plurality of preview images mentioned in Step 230) fallswithin a range of a predetermined interval. Namely, the differencebetween the scales of the specific preview image and any preview image(e.g. any of the plurality of preview images) may fall in an allowedrange rather than just equal to zero. The manner this way can be seen asa quasi-scale-invariant manner.

In practice, the specific focus-related parameter can be an autofocuscontrol parameter that is utilized for performing the aforementionedautofocus control on the camera module 50, for example. Moreparticularly, the specific focus-related parameter can be a digitalvalue to be applied to a digital-to-analog converter (DAC), where theDAC can be positioned on a control path of the camera module 50. Forexample, the camera module 50 may comprise a lens unit and an imagesensor, where the lens unit and the image sensor are arranged forobtaining the specific preview image. In addition, the camera module mayfurther comprise a motor that is arranged for changing the distancebetween the lens unit and the image sensor, where the digital valueapplied to the DAC is utilized for controlling the motor.

According to some embodiments, the specific focus-related parameter isassociated to an autofocus status of the camera module 50. For example,the autofocus status may represent the distance between the lens unitand the image sensor in the above embodiments. In some examples, theautofocus status may represent a certain control position of the motor.In other examples, the autofocus status may represent a DAC index, suchas the digital value.

The preview images can be displayed in the scale-invariant manner, andthe focus control module 110 may control the apparatus 100 to set thefocus-related parameters to obtain the preview images of the specificfocus setting, respectively, where the focus-related parameterscomprises the specific focus-related parameter. In addition, the resizecontrol module 120 may determine the resize parameters corresponding tothe preview images according to the predetermined relationships betweenthe resize parameters and the focus-related parameters, respectively,where the resize parameters comprise the specific resize parameter. Moreparticularly, the image resize module 130 may perform a plurality ofresize operations on the preview images according to the resizeparameters, respectively, to control the preview images to be displayedin the scale-invariant manner.

Please note that, typically, both of the displayed version of thespecific preview image and the displayed version of another previewimage may have the same object. For the object shown in both of thedisplayed versions of the specific preview image and the other previewimage, the size and the position of the object are invariant. Moreparticularly, all of the preview images may have the same imagecontents, except that at least one portion (e.g. a portion or all) ofthe preview images may be not clear enough (e.g. one or more previewimages may look vague) due to failure of imaging.

In one embodiment, the resize control module 120 may obtain thepredetermined relationship between the specific resize parameter and thespecific focus-related parameter from a lookup table (LUT). Moreparticularly, different portions of the LUT, such as a plurality ofpartial LUTs within the LUT, may indicate the predeterminedrelationships between the resize parameters and the focus-relatedparameters, respectively. As a result, the resize control module 120 mayobtain any predetermined relationship of the predetermined relationshipsfrom the LUT.

In another embodiment, the resize control module 120 may obtain theaforementioned predetermined relationship between the specific resizeparameter and the specific focus-related parameter from a predeterminedmodel according to a set of predetermined data. For example, the resizecontrol module 120 may obtain the set of predetermined data from a LUT,where this LUT can be the same as a partial LUT within the plurality ofpartial LUTs mentioned in the above embodiment. As a result, the resizecontrol module 120 may obtain some predetermined relationships from thisLUT, and may obtain other predetermined relationships from thepredetermined model according to the set of predetermined data since theother predetermined relationships can be derived by performing modelfitting of the predetermined model according to the set of predetermineddata.

The resize control module 120 may perform a plurality of learningoperations according to a set of preview images (e.g. multiple previewimages that are different from the preview images mentioned in Step 230,such as some other preview images obtained in advance by using thecamera module 50), to generate a plurality of learning results,respectively, in advance. In addition, the resize control module 120 mayobtain the predetermined relationship between the specific resizeparameter and the specific focus-related parameter from a predeterminedmodel according to a specific learning result. For example, the resizecontrol module 120 may determine the learning results by statisticsmodel fitting. In some examples, the resize control module 120 mayobtain a plurality of user inputs from a UI of the electronic device(e.g. a set of physical buttons of the electronic device, or a set ofvirtual buttons displayed on a touch sensitive display module of theelectronic device), where the user inputs corresponds to the set ofpreview images, respectively. More particularly, the resize controlmodule 120 may perform the learning operations according to the set ofpreview images and the user inputs to generate the learning results,respectively, in advance. As a result, the resize control module 120 mayobtain the predetermined relationships from the predetermined modelaccording to an associated learning result of the plurality of learningresults.

FIG. 3 illustrates the visual effect of a scale-invariant previewcontrol scheme according to an embodiment of the present invention.During an autofocus procedure, these preview images may have two visualeffects, one is the ‘blur effect’, and another one is the ‘scalingeffect’. The ‘blur effect’ can be represented by different widths ofobject contour lines, and the ‘scaling effect’ can be represented byresizing the object. The upper row of preview images in FIG. 3 shows thescale-invariant results (with the ‘blur effect’ only) that are obtainedfrom the scale-invariant preview control scheme, and the lower row ofpreview images in of FIG. 3 shows the scale-variant results of theconventional autofocus procedure (with both of the ‘blur effect’ and the‘scaling effect’). For better comprehension, a square printed on a testchart can be taken as an example of the same video object that is shownin the two rows of preview images shown in FIG. 3.

Within the preview images in the upper row of preview images shown FIG.3, the first preview image (i.e. the leftmost preview image in this row)is not clear, the second preview image (i.e. the one next to theleftmost preview image in this row) is clearer, the third preview image(i.e. the one next to the rightmost preview image in this row) iscorrectly focused and clearest, and the fourth preview image (i.e. therightmost preview image in this row) is not so clear again because offar away from the focus position in the opposite direction. In addition,the apparatus 100 may control the upper row of preview images to bedisplayed in the scale-invariant manner or the quasi-scale-invariantmanner. As a result, the size of the video object (e.g. the squareprinted on the test chart) shown in any preview image of the upper rowof preview images looks the same as that of the video object shown inany other preview image of the upper row of preview images. Regardingthe conventional autofocus procedure, the degree of clearness of apreview image in the lower row of preview images may be similar to thatof a preview image in the upper row of preview images. However, theconventional architecture of the related art typically controls thelower row of preview images to be displayed in a scale-variant manner.As a result, the size of the video object (e.g. the square printed onthe test chart) shown in any preview image of the lower row of previewimages is different from that of the video object shown in any otherpreview image of the lower row of preview images. For example, duringthe conventional autofocus procedure, the size of the video objectdecreases as shown in the lower row of preview images, and the user'svisually annoyed feeling is caused thereby.

According to this embodiment, in a situation where the preview imagesmentioned in Step 230 are obtained and processed by the apparatus 100,the apparatus 100 may process the preview images according to thescale-invariant preview control scheme involved with the method shown inFIG. 2. More particularly, the image resize module 130 may perform theresize operations on the preview images according to the resizeparameters, respectively, to control the preview images to be displayedin the scale-invariant manner. As a result, all of the preview imagesmay have the same image contents, except that at least one portion (e.g.a portion or all) of the preview images, may be not clear enough due tofailure of imaging.

Please note that, as the preview images can be displayed in thescale-invariant manner, the method 200 and the associated apparatus 100can bring better user experience to the user, where the related artproblems can be prevented.

FIG. 4 illustrates an ISP (Image Signal Processor) 400 involved with themethod 200 shown in FIG. 2 according to an embodiment of the presentinvention, where the ISP 400 can be taken as an example of the ISPmentioned in some embodiments described between the embodimentsrespectively shown in FIG. 1 and FIG. 2.

As shown in FIG. 4, the ISP 400 may comprise an image resize module 430,a focus control module 410, a resize control module 420, an autofocuscontrol circuit 450, and a scale-invariant control circuit 440, and mayfurther comprise an autofocus statistics module (not shown) integratedinto the autofocus control circuit 450.

The autofocus control circuit 450 is arranged for autofocus process,i.e. searching the best focus setting from the focus statistics of thepreview images to obtain the best sharp image. Particularly, during theprocess of the autofocus control circuit 450, the scale-invariantcontrol circuit 440 generates the specific focus-related parameter,wherein the statistic focus result is generated from the autofocusstatistics module. In addition to the specific focus-related parameter,the scale-invariant control circuit 440 determines a specific resizeparameter corresponding to the specific preview image according to apredetermined relationship between the specific resize parameter and thespecific focus-related parameter.

The flow diagram shown in FIG. 4 can be referred to as an example of theembodiments respectively shown in FIG. 1 and FIG. 2. For example, thefocus control module 410 can be taken as an example of the focus controlmodule 110, and the scale-invariant control circuit 440 can be taken asan example of the scale-invariant control circuit 140. The apparatus100-1 shown in FIG. 4 can be taken as an example of the apparatus 100shown in FIG. 1, where the apparatus 100-1 of this embodiment maycomprise the whole of the electronic device mentioned above. Forbrevity, similar descriptions for this embodiment are not repeated indetail here.

FIG. 5 illustrates a set of predetermined relationships involved withthe method 200 shown in FIG. 2 according to an embodiment of the presentinvention, where the function indicated by the curve shown in FIG. 5comprises the set of predetermined relationships, i.e. the predeterminedrelationships between the coordinate values of the resizing ratio andthe coordinate values of the DAC indexes (more particularly, the digitalvalues to be applied to the DAC mentioned above).

According to this embodiment, the horizontal axis may correspond to thefocus-related parameters, and the vertical axis may correspond to theresize parameters. Please note that the set of predeterminedrelationships in this embodiment, such as the points on the curve shownin FIG. 5, can be taken as an example of the predeterminedrelationships, where a specific predetermined relationship within theset of predetermined relationships in this embodiment, such as aspecific point on the curve shown in FIG. 5, can be taken as an exampleof the predetermined relationship between the specific resize parameterand the specific focus-related parameter in Step 220. In practice, thecurve shown in FIG. 5 can be obtained by measuring the resizing ratiosof the set of preview images (e.g. the aforementioned multiple previewimages that are different from the preview images mentioned in Step230), such as the ratio of the size of a specific object of previewimages to the size of the same specific object in a reference previewimage.

FIG. 6 illustrates an ISP 600 involved with the method 200 shown in FIG.2 according to another embodiment of the present invention, where theISP 600 can be taken as an example of the ISP mentioned in someembodiments described between the embodiments respectively shown in FIG.1 and FIG. 2.

As shown in FIG. 6, the ISP 600 may comprise a focus control module 610,a resize control module 620, an image resize module 630, ascale-invariant control circuit 640, and an autofocus control circuit650, and may further comprise an autofocus statistics module (not shown)integrated into the autofocus control circuit 650. FIG. 4 and FIG. 6have different implementations of ISP. For the ISP 400, the autofocusstatistics module within the autofocus control circuit 450 processes theimages from the camera module 50 first, and then the image resize module430 follows to process thereafter. But for the ISP 600, the image resizemodule 630 processes the images from the camera module 50 first, andthen the autofocus statistics module within the autofocus controlcircuit 650 follows to process thereafter.

The related diagram of FIG. 6 can be referred to as an example of theembodiments respectively shown in FIG. 1 and FIG. 2. For example, thefocus control module 610 can be taken as an example of the focus controlmodule 110, and the scale-invariant control circuit 640 can be taken asan example of the scale-invariant control circuit 140. The apparatus100-2 shown in FIG. 6 can be taken as an example of the apparatus 100shown in FIG. 1, where the apparatus 100-2 of this embodiment maycomprise the whole of the electronic device mentioned above. Forbrevity, similar descriptions for this embodiment are not repeated indetail here.

FIG. 7 illustrates a sensor system on chip (SOC) architecture 700(labeled “Sensor SOC” in FIG. 7, for brevity) involved with the method200 shown in FIG. 2 according to another embodiment of the presentinvention, where the sensor SOC architecture 700 can be taken as anexample of the image sensor with the focus control module 110, theresize control module 120, and the image resize module 130 beingintegrated into the image sensor as mentioned in some embodimentsdescribed between the embodiment shown in FIG. 1 and the embodimentshown in FIG. 2.

As shown in FIG. 7, the sensor SOC architecture 700 may comprise a focuscontrol module 710, a resize control module 720, an image resize module730, a scale-invariant control circuit 740, and an autofocus controlcircuit 750, and may further comprise an autofocus statistics module(not shown) integrated into the autofocus control circuit 750, and mayfurther comprise an autofocus camera sub-module 50SUB, where theautofocus camera sub-module 50SUB may comprise at least one image sensorarray and the associated image sensor control circuits, and may comprisea driving circuit of the motor of this embodiment, and the DAC mentionedcan be integrated into the driving circuit of this embodiment. Based onthe arrangement shown in FIG. 7, the camera module 700C of thisembodiment may comprise the sensor SOC architecture 700, (e.g. the motordriven by the driving circuit), and the lens unit mentioned in some ofthe above embodiments.

Please note that the autofocus statistics module integrated into theautofocus control circuit 750 of this embodiment is coupled between theautofocus camera sub-module 50SUB and the image resize module 730.Further, in a situation where all of the focus control module 110, theresize control module 120, the image resize module 130, andscale-invariant control circuit 140 shown in FIG. 1 are integrated intothe image sensor of the camera module 50 shown in FIG. 1, the cameramodule 700C can be taken as an example of the camera module 50. As shownin FIG. 7, the apparatus 100-3 may comprise the camera module 700C, andmay further comprise an ISP 80 arranged for performing image processing.

The related diagram shown in FIG. 7 can be referred to as an example ofthe embodiments respectively shown in FIG. 1 and FIG. 2. For example,the focus control module 710 can be taken as an example of the focuscontrol module 110, and the scale-invariant control circuit 740 can betaken as an example of the scale-invariant control circuit 140. Forexample, in a situation where all of the focus control module 110, theresize control module 120, the image resize module 130, andscale-invariant control circuit 140 shown in FIG. 1 are integrated intothe image sensor of the camera module 50 shown in FIG. 1, the apparatus100-3 shown in FIG. 7 can be taken as an example of the apparatus 100shown in FIG. 1, where the apparatus 100-3 of this embodiment maycomprise the whole of the electronic device mentioned above. Forbrevity, similar descriptions for this embodiment are not repeated indetail here.

FIG. 8 illustrates a working flow 800 involved with the method 200 shownin FIG. 2 according to an embodiment of the present invention, where theworking flow 800 can be applied to the apparatus 100-1 shown in FIG. 4.

In Step 801, the camera module 50 (e.g. an autofocus camera module)captures image raw data according to the focus setting such as the DACindex. For example, the initial value of the DAC index can be set as adefault value. More particularly, the initial value of the DAC index canbe the value corresponding to a hyper-focus plane.

In Step 802, the autofocus statistics module integrated into theautofocus control circuit 450 performs an autofocus analysis operationsuch as a focus value (FV) analysis operation. For example, theautofocus control statistics circuit 450 (or the autofocus statisticsmodule therein) may obtain the associated FV of the image raw datamentioned in Step 801 from the FV analysis, where the associated FV mayindicate the focus quality of the image having the image raw data, andtherefore may indicate whether this image is clear or not.

In Step 803, the resize control module 420 obtains the resize settingaccording to the focus setting from a predetermined relationship source(e.g. a mapping function of the predetermined model mentioned above, ora LUT such as that mentioned above).

In Step 804, the resize control module 420 and the focus control module410 apply the resize setting and the focus setting, respectively.

In Step 804-1, the resize control module 420 sets the new resize settingto the image resize module 430. As a result, the image resize module 430resizes the image according to the resize setting.

In Step 804-2, the focus control module 410 sets the new focus settingto the camera module 50 (e.g. the autofocus camera module mentioned inStep 801).

After the operations of Step 804 are performed, Step 801 is re-entered.For brevity, similar descriptions for this embodiment are not repeatedin detail here.

FIG. 9 illustrates a working flow 900 involved with the method 200 shownin FIG. 2 according to another embodiment of the present invention,where the working flow 900 can be applied to the apparatus 100-2 shownin FIG. 6.

In Step 901, the camera module 50 (e.g. an autofocus camera module suchas that mentioned above) captures image raw data according to the focussetting such as the DAC index. For example, the initial value of the DACindex can be set as a default value. More particularly, the initialvalue of the DAC index can be the value corresponding to a hyper-focusplane.

In Step 902, the resize control module 620 obtains the resize settingaccording to the focus setting from a predetermined relationship source(e.g. a mapping function of the predetermined model mentioned above, ora LUT such as that mentioned above).

In Step 903, the resize control module 620 and the focus control module610 apply the resize setting and the focus setting, respectively.

In Step 903-1, the focus control module 610 sets the new focus settingto the camera module 50 (e.g. the autofocus camera module mentioned inStep 901).

In Step 903-2, the resize control module 620 sets the new resize settingto the image resize module 630.

In Step 904, the image resize module 630 resizes the image according tothe resize setting.

In Step 905, the autofocus statistics module integrated into theautofocus control circuit 650 performs an autofocus analysis operationsuch as an FV analysis operation. For example, the autofocus controlcircuit 650 (or the autofocus statistics module therein) may obtain theassociated FV of the image raw data mentioned in Step 901 from the FVanalysis, where the associated FV may indicate the focus quality of theimage having the image raw data, and therefore may indicate whether thisimage is clear or not.

In Step 906, the focus control module 610 sets a new focus setting tothe camera module 50 (e.g. the autofocus camera module mentioned in Step901).

After the operation of Step 906 is performed, Step 901 is re-entered.For brevity, similar descriptions for this embodiment are not repeatedin detail here.

As mentioned in some embodiments described between the embodiment shownin FIG. 2 and the embodiment shown in FIG. 3, the resize control module120 may obtain the aforementioned predetermined relationship between thespecific resize parameter and the specific focus-related parameter fromthe LUT. For example, in one of these embodiments, the LUT can be amapping table such as that shown below:

DAC index 10 20 30 40 . . . 490 500 Resizing ratio 1.000 1.000 1.0011.002 . . . 1.095 1.100where the notation “ . . . ” in this table may represent some columns ofdata that are omitted since there are many. Please note that the DACindex in this table can be the same as that in the embodiment shown inFIG. 5, and the resizing ratio in this table can be the same as that inthe embodiment shown in FIG. 5. For brevity, similar descriptions forthis embodiment are not repeated in detail here.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A method for performing preview control in anelectronic device, the method comprising the steps of: obtaining aspecific preview image from a camera module of the electronic device,and obtaining a specific focus-related parameter corresponding to thespecific preview image, wherein the specific focus-related parameter isrelated to focus control of the camera module; determining a specificresize parameter corresponding to the specific preview image accordingto a predetermined relationship between the specific resize parameterand the specific focus-related parameter; and performing a resizeoperation on the specific preview image according to the specific resizeparameter, to control the specific preview image to be displayed in ascale-invariant manner with respect to a plurality of preview images. 2.The method of claim 1, wherein the specific focus-related parameter isan autofocus control parameter that is utilized for performing autofocuscontrol on the camera module.
 3. The method of claim 2, wherein thespecific focus-related parameter is a digital value to be applied to adigital-to-analog converter (DAC), and the DAC is positioned on acontrol path of the camera module.
 4. The method of claim 1, wherein thespecific focus-related parameter is associated to an autofocus status ofthe camera module.
 5. The method of claim 1, wherein the preview imagesare displayed in the scale-invariant manner; and the method furthercomprises: obtaining a plurality of focus-related parameterscorresponding to the preview images respectively, wherein thefocus-related parameters comprises the specific focus-related parameter;and determining a plurality of resize parameters corresponding to thepreview images according to a plurality of predetermined relationshipsbetween the resize parameters and the focus-related parametersrespectively, wherein the resize parameters comprises the specificresize parameter.
 6. The method of claim 5, wherein for an object thatis shown in both of a displayed version of the specific preview imageand a displayed version of another preview image of the preview images,a size of the object is invariant.
 7. The method of claim 6, wherein forthe object that is shown in both of the displayed version of thespecific preview image and the displayed version of the other previewimage of the preview images, a position of the object is invariant. 8.The method of claim 5, further comprising: performing a plurality ofresize operations on the preview images according to the resizeparameters, respectively, to control the preview images to be displayedin the scale-invariant manner.
 9. The method of claim 1, furthercomprising: obtaining the predetermined relationship between thespecific resize parameter and the specific focus-related parameter froma look up table (LUT).
 10. The method of claim 1, further comprising:obtaining the predetermined relationship between the specific resizeparameter and the specific focus-related parameter from a predeterminedmodel according to a set of predetermined data.
 11. The method of claim10, further comprising: obtaining the set of predetermined data from alook up table (LUT).
 12. The method of claim 1, further comprising:performing a plurality of learning operations according to a set ofpreview images, to generate a plurality of learning results,respectively; and obtaining the predetermined relationship between thespecific resize parameter and the specific focus-related parameter froma predetermined model according to a specific learning result of thelearning results.
 13. The method of claim 12, further comprising:obtaining a plurality of user inputs from a user interface (UI) of theelectronic device, wherein the user inputs corresponds to the set ofpreview images, respectively; wherein the step of performing thelearning operations according to the set of preview images to generatethe learning results respectively further comprises: performing thelearning operations according to the set of preview images and accordingto the user inputs, to generate the learning results respectively. 14.An apparatus for performing preview control in an electronic device, theapparatus comprising at least one portion of the electronic device, theapparatus comprising: a focus control module, arranged for controllingthe apparatus to obtain a specific preview image from a camera module ofthe electronic device, and obtaining a specific focus-related parametercorresponding to the specific preview image, wherein the specificfocus-related parameter is related to focus control of the cameramodule; a resize control module, coupled to the focus control module,arranged for determining a specific resize parameter corresponding tothe specific preview image according to a predetermined relationshipbetween the specific resize parameter and the specific focus-relatedparameter; and an image resize module, coupled to the resize controlmodule, arranged for performing a resize operation on the specificpreview image according to the specific resize parameter, to control thespecific preview image to be displayed in a scale-invariant manner withrespect to a plurality of preview images.
 15. The apparatus of claim 14,wherein the resize control module is integrated into the focus controlmodule.
 16. The apparatus of claim 14, wherein the focus control module,the resize control module, and the image resize module are positionedwithin an image signal processor (ISP); and the ISP is coupled to thecamera module.
 17. The apparatus of claim 14, wherein the focus controlmodule comprises an autofocus control circuit arranged for performingautofocus control of the camera module; and the apparatus furthercomprises: an autofocus statistics module, coupled between the cameramodule and the image resize module, and further coupled to the autofocuscontrol circuit, arranged for performing a plurality of autofocusstatistics operations on the preview images to generate a plurality ofautofocus statistics results respectively.
 18. A method for performingpreview control in an electronic device, the method comprising the stepsof: obtaining a specific preview image from a camera module of theelectronic device, and obtaining a specific focus-related parametercorresponding to the specific preview image, wherein the specificfocus-related parameter is related to focus control of the cameramodule; determining a specific resize parameter corresponding to thespecific preview image according to a predetermined relationship betweenthe specific resize parameter and the specific focus-related parameter;and performing a resize operation on the specific preview imageaccording to the specific resize parameter, to control the specificpreview image to be displayed in a quasi-scale-invariant manner withrespect to a plurality of preview images, wherein thequasi-scale-invariant manner represents that an image scale differencebetween the specific preview image and any preview image falls within apredetermined range.
 19. The method of claim 18, wherein the specificfocus-related parameter is a digital value to be applied to adigital-to-analog converter (DAC), and the DAC is positioned on acontrol path of the camera module.
 20. The method of claim 18, whereinthe preview images are displayed in the quasi-scale-invariant manner;and the method further comprises: obtaining a plurality of focus-relatedparameters corresponding to the preview images respectively, wherein thefocus-related parameters comprises the specific focus-related parameter;and determining a plurality of resize parameters corresponding to thepreview images according to a plurality of predetermined relationshipsbetween the resize parameters and the focus-related parametersrespectively, wherein the resize parameters comprises the specificresize parameter.